


Copy & Paste

by LadyHallen



Category: Katekyou Hitman Reborn!
Genre: Angst, Feels, Flame Bullshittery, Fluff, Gen, Guns, Twin AU, Whump, flangst
Language: English
Status: Completed
Published: 2018-01-23
Updated: 2018-01-23
Packaged: 2019-03-08 13:29:39
Rating: Teen And Up Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 3,461
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/13459248
Author URL: https://archiveofourown.org/users/LadyHallen/pseuds/LadyHallen
Summary: "Sawada Natsuki does not exist," the baby said, voice high and squeaky in complete odds with the way the gun never wavered. "Not in the hospital records, or any records in fact. Until Sawada Tsunayoshi was four years old, he was an only child."So why then did Tsuna have a twin brother?





	Copy & Paste

**Author's Note:**

> This is my version of a Tsuna Twin Fic.
> 
> Warnings: Whump. Fluff. Angst. Flangst?

Tsuna's younger twin brother, Natsuki Sawada, tended to attract attention.

First, they'd see the two of them, then Tsuna would swear eyes would slide off him and go to his brother and stay there. They'd stare at him in...admiration? Then, Natsu would open his mouth and people's expressions would sour.

If Tsuna hadn't seen it happen first hand, he would never believe it. At home, Natsu was perfectly nice, a cuddly and sweet younger brother who's habits were making Tsuna laugh until he cried. Then, when he'd made Tsuna so weak, he'd crawl on the floor beside him and cuddle, something Tsuna would agree to if only Natsu would  _ask._

But, as Natsu always said, "asking makes people prepared. You must take them by surprise, Nii-chan, they make the best faces."

Tsuna would be  _concerned_  about raising Natsu wrong, but Natsu's face was always comically serious, a twinkle in his brown eyes that told Tsuna he didn't want to ask. He got the feeling that it would explain Hibari-senpai's full body twitch once at seeing Natsu, or the weirdly droopy hair the Disciplinary Committee had for that day.

So, after people had gotten used to Natsu's mouth, they would usually watch him with irritation or outright avoid him. Kurokawa Hana tended to call him an 'asshole', the English word foreign and very strange for someone very good at Japanese Lit and struggled with English class.

Still, it was the first time he'd seen someone point a gun at Natsu's head, before his brother had even opened his mouth.

Tsuna felt alarm racing up his spine, but he'd never seen a gun before, or used one. That his enemy was a very well-dressed toddler made it odd, but it was still a gun. A gun pointed at his precious baby brother's head.

"Sawada Natsuki does not exist," the baby said, voice high and squeaky in complete odds with the way the gun never wavered. "Not in the hospital records, or any records in fact. Until Sawada Tsunayoshi was four years old, he was an only child."

Natsu was unfairly calm at the face of a gun. Tsuna wanted to scream but he didn't want to draw the attention of the toddler.

"And who are you?" Natsu asked. Unlike Tsuna, there was no confusion at all in his face, which made something tingle at the back of Tsuna's head. He looked. Looked odd. He ... He was  _resigned?_

What was going on?

"You're not asking the questions here, impostor," the toddler said.

Natsu went stiff. "Don't call me that," he snapped.

Tsuna did not squeak. There was a deranged toddler trying to kill his younger brother and his brother just talked back. He'd seen enough Yakuza movies to see how his worked out.

Thankfully for Tsuna's blood pressure, the toddler did not shoot, or backhand his brother's face. Instead, the gun pointed to Tsuna, which finally made Natsu go as pale as milk, which was the state Tsuna had been since the gun came out.

"Don't," he pleaded. "Don't hurt him."

Tsuna felt sick. He'd never heard his brother sound like that.

"I'll tell you everything," Natsu continued, head bowed. "Please put the gun away."

The toddler's gun vanished...somewhere. But that serious face was still on. Tsuna's limbs felt stiff but he rushed to hug his brother. A hug always made things a bit better.

It would be better, but Natsu  _flinched._ Natsu, who initiated hugs,  _flinched away from him_. It would be understandable if Natsu didn't want to touch the toddler, who still watched them with that eerie, eagle-eyed expression. But Tsuna didn't hurt his brother.

"Natsu-chan," Tsuna whispered.

He didn't push, but...it stung.

.

* * *

.

It was the tensest atmosphere the kitchen had ever hosted.

Usually, it was a warm place, inviting and usually smelling of whatever food Kaa-chan had decided was good for the day.

It still smelled nice, the tea wafting out of the open window, but the atmosphere was tense. Almost as though Reborn, the toddler, still had his gun out and cocked.

"I'm not an impostor," Natsu said, voice soft. "I am myself."

Reborn tilted his head to the side, curly sideburns bouncing. It would be cute if Tsuna hadn't seen how menacing the toddler could get.

"Who are you, is the wrong question, isn't it?" Reborn stated, making the twins twitch at the sound of his voice. "It's supposed to be, 'What are you?'"

Natsu sighed and placed his hand on the table. His hand, a perfect copy of Tsuna's hand save for the different scars and callouses Natsu had from playing the violin and Tsuna from playing the guitar.

"I was made to be...a companion," Natsu said, eyes still on his hand. He didn't look anyone in the eye. Tsuna just felt cold.

"Initially, a companion," he continued. "But...I became a brother."

The tingle at the back of his head, the one that prodded at him and saved him so much trouble, acted up then. And...he knew.

Tsuna knew. That sick sensation he'd been feeling since seeing Reborn with a gun intensified. He knew, and he could no longer go back to being in denial.

He had known.

Natsu. Natsu had suddenly appeared when he was asleep, and he woke up with a look alike clutching his hand. Then Natsu had opened his eyes and smiled at Tsuna in complete adoration.

And Tsuna. Lonely Tsuna who had just had his mother for company for days on end, smiled back. Four years old and not knowing better, he'd named his apparition, his doppelganger and made him his brother.

And taught him how to be human.

Years, and Tsuna had forgotten.

That...that was a good question. What...was Natsu made of?

Natsu was looking at Tsuna now, and his eyes were sad. So sad. Come to think of it, he had never seen his brother cry, or bleed.

"You remember," Natsu whispered, wonder in his eyes and speaking as though it was just two of them and there was no Reborn. "I woke up holding you. And you held back. You were the first thing I saw, Nii-san."

Tsuna took in a breath and it hitched. "You smiled at me," Tsuna whispered back. "And I knew. I would never be alone again."

Natsu smiled, that same childish smile of Tsuna's memory. "Yes. Because you made me. You were so lonely, so desperate for a friend, that you wished me into existence."

There. It was said. The truth. The answer to Reborn's question.

Saying it out loud made it real. Natsu looked so pale.

"And I made you real, permanent, when I gave you a name," Tsuna continued, closing his eyes. He felt so cold.

"A flame construct," Reborn's high pitched voice interrupted, making both of them flinch.

"A what?"

.

* * *

.

Reborn was no longer hostile and giving off the impression of a cuddly baby. Tsuna wasn't about to fall for that though, not with the way he stared at Natsu with interest.

It would help if Natsu stopped looking so resigned. If he looked terrified or something. But he just sat there and kept quiet. Tsuna had seen Natsu humiliate Mochida with an innocent smile and sharp words only. His silence was putting him off-kilter.

"You have to let him go, Tsuna," Reborn said, as though he was talking about the weather. Like they weren't talking about murder.

"Why?" Tsuna asked. "He's not hurting anyone."

Reborn's lips pursed. "He's hurting you."

At that, Natsu finally came to life.

"How would he do that?" he asked, voice hoarse. "How am I hurting Nii-chan?"

Tsuna rounded on him. "You're not killing yourself!"

Both of them ignored him. Tsuna wanted to bang his head on the wall. It would certainly be more productive than arguing with a stubborn Natsu.

"Tsuna is supplying you with flames," Reborn said. "And flames are willpower. Willpower to live, or do anything. Have you ever noticed him tired after you touch him? Or sleeping at odd hours. Or even eating so much?"

Tsuna ignored the fact that Natsu barely ate. Tsuna ate enough for the both of them. He was a growing boy!

"No one is killing anyone," Tsuna growled out, making both of them startle. "Natsu, you're not killing yourself, or convincing me to kill you. Reborn. Don't even think about it."

There was a satisfied gleam in Reborn's eyes as he stared at Tsuna. Natsu just looked shocked.

"Nii-chan, you're eyes are orange," Natsu whispered, a hint of glee in his face making Tsuna hold back an involuntary smile. "It's so cool, it's like you're in an anime or something."

Tsuna snorted. "Natsu, this is not the time," he said, exasperated. The ice in his belly melted at Natsu acting like himself.

"Reborn," he addressed the hitman – toddler? For the first time. "Don't you have people to ask if they can make Natsu...here..without any murder?"

He deliberately did not say the word 'real'. Because Natsu was real, even if he didn't know where they stood now.

"Of course I do," the toddler said. "But why should I?"

That...that was the question, wasn't it?

He couldn't exactly appeal to Reborn's sense of morality. Reborn had no qualms killing, obviously. He had just attempted to murder Natsu before his need for information had taken over.

But.

But why did Reborn seem so angry at Natsu's existence?

 _How_  he knew Natsu's lack of medical records can be checked out in the hospital. They why here was...because of Tsuna?

That intuition prodded at him that he was at the right path.

"You're here," Tsuna said, which startled him. He did not mean to say that. "You're here because...I'm important? No, you're here because of something. Someone. Dad. You're here because he finally noticed Natsu."

That was correct. He never felt surer of something in his life.

"And Dad is someone important in this flames business, otherwise you wouldn't be here," Tsuna continued, feeling confident. "So you can go to his people. Because I'm not letting go of Natsu. And I'm going to die before I let you or anyone else hurt him."

There was a moment of silence.

"Congratulations, Baka-Tsuna, you have a spine," Reborn drawled out. "But don't do that again. You can't presume to order me around."

Natsu scared Tsuna out of his mind though, jumping on Tsuna and squeezing him hard. "Nii-chan," he blubbered.

His little brother. His younger brother. His baby brother. Who was only nine years old, if he was counting right. He did raise Natsu. He taught him everything he knew.

Then the internet and anime happened.

"Natsu-chan," he whispered back, feeling warm again. The ice at the pit of his stomach was gone and he hugs his baby brother back.

.

* * *

.

Later, when they're alone in their room and Reborn finally left them alone, Tsuna spoke.

"Did I make you love me?" Tsuna asked. His voice cracked on the last syllable. "You said. That I  _made_  you to be a companion."

Natsu, who was curled around him, cuddled him tighter. Their faces were inches from each other.

"Nii-chan. Tsuna," Natsu said firmly. "I woke up. I opened my eyes and I saw you. You were the first one I ever saw. The first person I ever touched."

Natsu pushed his face to Tsuna's neck. "I didn't know anything. I didn't know  _anyone._  I could have been so many things. I was a blank space, brother. But. You named me. You made me your brother. You could have turned me away. But you named me."

Natsu's voice was muffled over Tsuna's chest, but he still heard his words clearly. The hand stroking Natsu's hair was trembling. Maybe both of them were. It certainly felt like it.

"You made me your friend," Natsu continued. "But I loved you on my own. It was easy to love you, Nii-chan."

The sob that had been building up Tsuna's throat finally gave out and he let it out.

Natsu couldn't cry. Tsuna understood that now. He could taste, he could feel, but expelling things from his flame body made him weaker, so he couldn't cry.

But he certainly sounded like he was.

.

* * *

.

Reborn vanished for three days, and came back with a person, another toddler in tow.

"This is Mammon," Reborn introduced. "They're very good at sorting out your type of...problem."

Mammon, a toddler cloaked in head to toe in deep purple, looked at the both of them and sighed.

"Mou. Reborn, this would be easier if he has guardians. If not a Sun, then a Cloud or a Mist," Mammon complained. "I can't work with nothing."

A speculative gleam entered Reborn's eyes. "Hmm, yes. Say, Tsuna. How is your relationship with Hibari Kyoya?"

Tsuna felt  _uncomfortable_.

.

* * *

.

Whatever Reborn did, it made Hibari descend upon the Sawada Twins like a vengeful god of wrath on school the next day.

Tsuna should have listened to his intuition and stayed at home, pretending to be sick.

He shrieked and ran, Natsu right beside him as they tried to avoid the murderously angry prefect. Something about Hibari's face told Tsuna that he was  _serious_  about hitting them with his tonfa's.

A pebble hit Natsu at the back of his knee, making him stumble. Hibari caught the weakness immediately and swung his tonfa.

Tsuna didn't even know he was moving until he was, hands crossed over his face and body curled protectively over Natsu, his teeth bared in a snarl and eyes orange.

"Don't touch him," Tsuna growled.

A spark of something aside from anger finally showed in Hibari's face.

"Interesting," Hibari said. "That should have broken your arm."

Now that the adrenaline was fading, it did hurt like hell. But Tsuna was still pissed off. People disliked Natsu but never bullied him. Tsuna may have been occasionally bullied, but Natsu discouraged that with his mouth.

Of the two of them, Tsuna was used to being pushed around.

"Touch him and  _I'll_ break your arm," Tsuna snapped.

Hibari smirked, anger finally gone from his face. "The roof at lunch. Or I'm coming for him."

Reborn popped out of nowhere. "Congratulations in Cloud courting," he chirped. He was dressed as a blade of grass. A very dangerous looking blade of grass, with actual blades coming out of the sides.

Then his words registered.

"Cloud courting?" he demanded. It sounded bad. Mostly because Reborn was  _happy_  about it.

"Attracting the attention of a Cloud flame user. They're notoriously difficult to attract, you know. So you should be pleased," Reborn explained.

The notion of being  _pleased_  that he'd attracted  _Hibari's_  attention just did not compute. The  _idea_  that there were more people like Hibari broke Tsuna's brain.

Natsu, beloved little brother, squeaked out, "There are more people like Hibari?"

Reborn twitched. "No. He's...a Hibari."

.

* * *

.

Lunch arrived too soon, which was strange, because time seemed to move so slow too. His forearms had tonfa-shaped bruises.

Reborn, being not the sadistic bastard for once, had given him arm guards and leather gloves.

Tsuna just wanted to know what universe he'd fallen into that he could go up to the roof to spar with Hibari  _willingly_.

Natsu, followed behind Tsuna every step of the way, in no way making it easier for Tsuna at all.

"You are a complete idiot for doing this," Natsu said flatly. "Did your brain overheat with all that flame nonsense? Tsuna-nii, there was a time when we knew where Hibari was, you know? So we can run in the opposite direction?"

Tsuna tried to ignore his brother. That was difficult. Natsu could be as tenacious as a barnacle on his stubborn days.

"Oh god, what did that baby dose you with?" Natsu groaned, sounding a tinge bit more resigned. But Tsuna didn't let that fool him. If Natsu sensed weakness, he'd pounce. "Where was the common sense you used last week with Mochida and his friends?"

Tsuna checked the straps on his hands for mobility and braced himself before opening the door to the roof.

Natsu sighed, long and deep, making Tsuna twitch.

"I can't stop you," he murmured. "But. Be careful? If he even breaks a single bone in your body, I'll get even."

There was an unsettling glint in Natsu's eyes. But. If Tsuna stopped long enough to analyse  _that_ , then he'd stop long enough to  _think_ , which was not conducive before fighting Hibari.

Fortunately for Tsuna, Hibari didn't give him time to think.

The moment Tsuna stepped on the roof, Hibari pounced.

Tsuna didn't squeak, he braced himself on his feet and surged back, ducking low aiming for the stomach.

The prefect was too fast and Tsuna had to sacrifice his shoulder instead of say, his neck.

What followed after was a pattern of rough, sharp jabs all aimed at Tsuna's head. He didn't know how, but he kept dodging tonfa strikes, and getting hit instead of being brutally maimed when dodging wasn't feasible.

And sometimes, the fire in him, the one that Reborn called Flames, surged forward and gave him strength behind his jabs. Intuition told him where and when to hit.

With all of that, he wasn't surprised that he was defeated. This was Hibari, after all.

What surprised him was the blood trickling out of the corner of Hibari's mouth and the torn sleeve he was sporting.

Oh god, he'd just torn  _Hibari's clothes._  He was going to die.

.

* * *

.

Somehow, he hadn't died.

Tsuna stared stupidly while Natsu fretted, muttering dire threats under his breath for the prefect. He would be more concerned if he had the energy to spare for it. An unattended, irritated Natsu was just asking for trouble.

"Good job, Baka-Tsuna," Reborn's voice squeaked  _right next to his ear_ , making both twins do a full body shudder. Tsuna curbed the instinct to punch. He had almost died enough times today, thank you. No need to commit seppuku via toddler.

"Good job on what?" Natsu spat out, still seething. "Not dying? Not dashing his brains on Hibari's tonfa's? Because I saw that nearly happen several times. Fucking tonfas. Those are getting a makeover." He rounded on Reborn. "Look at his head, I don't know enough about concussions to check for one."

Reborn must have been in a good mood, because he humoured Natsu's order. Tsuna only twitched once when Reborn landed on his good shoulder, peering at his scalp and touching it with his small hands. Otherwise, he stayed still, perfectly aware of the stronger predator perching on him.

'This must be what a bird perch of an eagle feels like,' Tsuna mused, still coming down from the adrenaline rush and not all there.

"Good job on getting a Cloud Guardian," Reborn said, looking so smug. "Now, we can solve your flame construct problem."

Natsu ignored Reborn. "Baka-Nii-chan. What do you think of pink tonfa's?"

The imagery made Tsuna break out in hives, effectively jerking him out of his shock.

"Hiieee, Natsu, don't do it!"

.

* * *

.

Mammon's solution was simple.

They gave Natsu a purple gemstone hung on a chain, telling him to be around the prefect for a week, in a maximum of a five mile radius.

Mostly hidden unless you knew where to look for it was the orange center, where Tsuna had been instructed to place his flames. Mammon had only had to keep it in place with their own indigo flames.

Cloud Flames being propagation, it would keep the small orange flames propagated so that Natsu could live and not hurt Tsuna.

Reborn thought it was the perfect solution. Tsuna thought it was just asking for trouble.

Hibari wanted Natsu bloody, Natsu could not stand Hibari. With Natsu's mouth and Hibari's propensity for biting irritants to death, it was a match made in hell.

It gave him so much gray hairs.

"It's alright, Nii-chan," Natsu said, glee in his voice. "At least this way, I can practice all the stealth training that Mammon was teaching me."

Oh god, his baby brother had hung out with that creepy toddler. Who knows what they were teaching Natsu?

.

* * *

.

Reborn ducked his head as he watched the Young Lion of Vongola's son and his flame construct.

If you didn't know where to look, they would be twins.

But Reborn had been looking for a week, and he knew where to look.

There, where Natsu's heart should have glowed with flames, was a hole. To his Sun flame tinged eyes, Natsu  _leaked._

"I hope your trust isn't misplaced on that construct, Tsunayoshi," he whispered. "The last one didn't end so well."

His thoughts drifted to Elena and Daemon Spade. As it had since he'd realized what the interloper, Sawada Natsuki, was.

Daemon Spade, the construct that had gone mad at the death of its master.

.

* * *

**Author's Note:**

> I am also available in [tumblr](http://ladyhallen.tumblr.com) for much screaming over this one. Because I love this, and I hope you love it as much as I do.


End file.
